386 research outputs found
Population dynamics of DENV-1 genotype V in Brazil is characterized by co-circulation and strain/lineage replacement
Following successive outbreaks of dengue fever caused predominantly by dengue virus (DENV) 2 and 3, DENV-1 is now the primary serotype circulating in Brazil. We sequenced and analyzed Brazilian DENV-1 genomes and found that all isolates belong to genotype V and are subdivided into three lineages, which were introduced during four different events. The first introduction occurred in 1984-85, the second in 1997-99, and the third and fourth occurred from 2004 to 2007. These events were associated with an increase in genetic diversity but not with positive selection. Moreover, a potential new recombinant strain derived from two distinct lineages was detected. We demonstrate that the dynamics of DENV-1 in Brazil is characterized by introduction, movement, local evolution, and lineage replacement. This study strengthens the relevance of genotype surveillance in order to identify, trace, and control virus populations circulating in Brazil and Latin America.Conselho Nacional de Pesquisas (Brazil) Conselho Nacional de Desenvolvimento Cientifico e TecnologicoFundaçaÌo de Amparo aÌ Pesquisa do Estado de Minas Gerai
Emergence of healing in the Antarctic ozone layer
Industrial chlorofluorocarbons that cause ozone depletion have been phased out under the Montreal Protocol. A chemically driven increase in polar ozone (or âhealingâ) is expected in response to this historic agreement. Observations and model calculations together indicate that healing of the Antarctic ozone layer has now begun to occur during the month of September. Fingerprints of September healing since 2000 include (i) increases in ozone column amounts, (ii) changes in the vertical profile of ozone concentration, and (iii) decreases in the areal extent of the ozone hole. Along with chemistry, dynamical and temperature changes have contributed to the healing but could represent feedbacks to chemistry. Volcanic eruptions have episodically interfered with healing, particularly during 2015, when a record October ozone hole occurred after the Calbuco eruption.National Science Foundation (U.S.) (FESD Grant OCE-1338814)National Science Foundation (U.S.). Atmospheric Chemistry Program (Grant 1539972
Self-reported pregnancy exposures and placental DNA methylation in the MARBLES prospective autism sibling study.
Human placenta is a fetal-derived tissue that offers a unique sample of epigenetic and environmental exposures present in utero. In the MARBLES prospective pregnancy study of high-risk younger siblings of children with autism spectrum disorder (ASD), pregnancy and environmental factors collected by maternal interviews were examined as predictors of placental DNA methylation, including partially methylated domains (PMDs), an embryonic feature of the placental methylome. DNA methylation data from MethylC-seq analysis of 47 placentas of children clinically diagnosed at 3 years with ASD or typical development using standardized assessments were examined in relation to: child's gestational age, birth-weight, and diagnosis; maternal pre-pregnancy body mass index, smoking, education, parity, height, prenatal vitamin and folate intake; home ownership; pesticides professionally applied to lawns or gardens or inside homes, pet flea/tick pouches, collars, or soaps/shampoos used in the 3 months prior to or during pregnancy. Sequencing run, order, and coverage, and child race and sex were considered as potential confounders. Akaike information criterion was used to select the most parsimonious among candidate models. Final prediction models used sandwich estimators to produce homoscadisticity-robust estimates of the 95% confidence interval (CI) and P-values controlled the false discovery rate at 5%. The strongest, most robust associations were between pesticides professionally applied outside the home and higher average methylation over PMDs [0.45 (95% CI 0.17, 0.72), P = 0.03] and a reduced proportion of the genome in PMDs [-0.42 (95% CI - 0.67 to -0.17), P = 0.03]. Pesticide exposures could alter placental DNA methylation more than other factors
A tetraspecific VHH-based neutralizing antibody modifies disease outcome in three animal models of Clostridium difficile infection
Clostridium difficile infection (CDI), a leading cause of nosocomial infection, is a serious disease in North America, Europe, and Asia. CDI varies greatly from asymptomatic carriage to life-threatening diarrhea, toxic megacolon, and toxemia. The incidence of community-acquired infection has increased due to the emergence of hypervirulent antibiotic-resistant strains. These new strains contribute to the frequent occurrence of disease relapse, complicating treatment, increasing hospital stays, and increasing morbidity and mortality among patients. Therefore, it is critical to develop new therapeutic approaches that bypass the development of antimicrobial resistance and avoid disruption of gut microflora. Here, we describe the construction of a single heteromultimeric VHH-based neutralizing agent (VNA) that targets the two primary virulence factors of Clostridium difficile, toxins A (TcdA) and B (TcdB). Designated VNA2-Tcd, this agent has subnanomolar toxin neutralization potencies for both C. difficile toxins in cell assays. When given systemically by parenteral administration, VNA2-Tcd protected against CDI in gnotobiotic piglets and mice and to a lesser extent in hamsters. Protection from CDI was also observed in gnotobiotic piglets treated by gene therapy with an adenovirus that promoted the expression of VNA2-Tcd
Improved Standardization of Type II-P Supernovae: Application to an Expanded Sample
In the epoch of precise and accurate cosmology, cross-confirmation using a
variety of cosmographic methods is paramount to circumvent systematic
uncertainties. Owing to progenitor histories and explosion physics differing
from those of Type Ia SNe (SNe Ia), Type II-plateau supernovae (SNe II-P) are
unlikely to be affected by evolution in the same way. Based on a new analysis
of 17 SNe II-P, and on an improved methodology, we find that SNe II-P are good
standardizable candles, almost comparable to SNe Ia. We derive a tight Hubble
diagram with a dispersion of 10% in distance, using the simple correlation
between luminosity and photospheric velocity introduced by Hamuy & Pinto 2002.
We show that the descendent method of Nugent et al. 2006 can be further
simplified and that the correction for dust extinction has low statistical
impact. We find that our SN sample favors, on average, a very steep dust law
with total to selective extinction R_V<2. Such an extinction law has been
recently inferred for many SNe Ia. Our results indicate that a distance
measurement can be obtained with a single spectrum of a SN II-P during the
plateau phase combined with sparse photometric measurements.Comment: ApJ accepted version. Minor change
Therapist Adherence in the Strong Without Anorexia Nervosa (SWAN) Study: A Randomized Controlled Trial of Three Treatments for Adults with Anorexia Nervosa
The Authors. International Journal of Eating Disorders Published by Wiley Periodicals, Inc.
This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.Objective: To develop a psychotherapy
rating scale to measure therapist adherence
in the Strong Without Anorexia
Nervosa (SWAN) study, a multi-center
randomized controlled trial comparing
three different psychological treatments
for adults with anorexia nervosa. The
three treatments under investigation
were Enhanced Cognitive Behavioural
Therapy (CBT-E), the Maudsley Anorexia
Nervosa Treatment for Adults (MANTRA),
and Specialist Supportive Clinical
Management (SSCM).
Method: The SWAN Psychotherapy Rating
Scale (SWAN-PRS) was developed, after
consultation with the developers of the
treatments, and refined. Using the SWANPRS,
two independent raters initially
rated 48 audiotapes of treatment sessions
to yield inter-rater reliability data. One
rater proceeded to rate a total of 98
audiotapes from 64 trial participants.
Results: The SWAN-PRS demonstrated
sound psychometric properties, and
was considered a reliable measure of
therapist adherence. The three treatments
were highly distinguishable by
independent raters, with therapists
demonstrating significantly more
behaviors consistent with the actual
allocated treatment compared to the
other two treatment modalities. There
were no significant site differences in
therapist adherence observed.
Discussion: The findings provide support
for the internal validity of the SWAN
study. The SWAN-PRS was deemed suitable
for use in other trials involving CBT-E,
MANTRA, or SSCM. VC 2015 The Authors.
International Journal of Eating Disorders
Published by Wiley Periodicals, Inc
Selenoprotein gene nomenclature
The human genome contains 25 genes coding for selenocysteine-containing proteins (selenoproteins). These proteins are involved in a variety of functions, most notably redox homeostasis. Selenoprotein enzymes with known functions are designated according to these functions: TXNRD1, TXNRD2, and TXNRD3 (thioredoxin reductases), GPX1, GPX2, GPX3, GPX4 and GPX6 (glutathione peroxidases), DIO1, DIO2, and DIO3 (iodothyronine deiodinases), MSRB1 (methionine-R-sulfoxide reductase 1) and SEPHS2 (selenophosphate synthetase 2). Selenoproteins without known functions have traditionally been denoted by SEL or SEP symbols. However, these symbols are sometimes ambiguous and conflict with the approved nomenclature for several other genes. Therefore, there is a need to implement a rational and coherent nomenclature system for selenoprotein-encoding genes. Our solution is to use the root symbol SELENO followed by a letter. This nomenclature applies to SELENOF (selenoprotein F, the 15 kDa selenoprotein, SEP15), SELENOH (selenoprotein H, SELH, C11orf31), SELENOI (selenoprotein I, SELI, EPT1), SELENOK (selenoprotein K, SELK), SELENOM (selenoprotein M, SELM), SELENON (selenoprotein N, SEPN1, SELN), SELENOO (selenoprotein O, SELO), SELENOP (selenoprotein P, SeP, SEPP1, SELP), SELENOS (selenoprotein S, SELS, SEPS1, VIMP), SELENOT (selenoprotein T, SELT), SELENOV (selenoprotein V, SELV) and SELENOW (selenoprotein W, SELW, SEPW1). This system, approved by the HUGO Gene Nomenclature Committee, also resolves conflicting, missing and ambiguous designations for selenoprotein genes and is applicable to selenoproteins across vertebrates
Initial experience with an electron FLASH research extension (FLEX) for the Clinac system
Purpose: Radiotherapy delivered at ultra-high-dose-rates (â„40 Gy/s), that is, FLASH, has the potential to effectively widen the therapeutic window and considerably improve the care of cancer patients. The underlying mechanism of the FLASH effect is not well understood, and commercial systems capable of delivering such dose rates are scarce. The purpose of this study was to perform the initial acceptance and commissioning tests of an electron FLASH research product for preclinical studies.
Methods: A linear accelerator (Clinac 23EX) was modified to include a nonclinical FLASH research extension (the Clinac-FLEX system) by Varian, a Siemens Healthineers company (Palo Alto, CA) capable of delivering a 16 MeV electron beam with FLASH and conventional dose rates. The acceptance, commissioning, and dosimetric characterization of the FLEX system was performed using radiochromic film, optically stimulated luminescent dosimeters, and a plane-parallel ionization chamber. A radiation survey was conducted for which the shielding of the pre-existing vault was deemed sufficient.
Results: The Clinac-FLEX system is capable of delivering a 16 MeV electron FLASH beam of approximately 1 Gy/pulse at isocenter and reached amaximum dose rate \u3e3.8 Gy/pulse near the upper accessory mount on the linac gantry. The percent depth dose curves of the 16 MeV FLASH and conventional modes for the 10 Ă 10 cm2 applicator agreed within 0.5 mm at a range of 50% of the maximum dose. Their respective profiles agreed well in terms of flatness but deviated for field sizes \u3e10 Ă 10 cm2. The output stability of the FLASH system exhibited a dose deviation of \u3c1%.Preliminary cell studies showed that the FLASH dose rate (180 Gy/s) had much less impact on the cell morphology of 76N breast normal cells compared to the non-FLASH dose rate (18 Gy/s), which induced large-size cells.
Conclusion: Our studies characterized the non-clinical Clinac-FLEX system as a viable solution to conduct FLASH research that could substantially increase access to ultra-high-dose-rate capabilities for scientists
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